Overview (Friday, April 21)
This weekend will turn noticeably cooler in the Mid-Atlantic region and there will be some rain to go along with that cool down; especially, south of the PA/MD border. We’ll then stay quite cool during the first half of next week, but a significant jump in temperatures is likely to arrive in the eastern US at the end of next week or during the following weekend. In fact, this surge of heat could result in the first 90 degree readings this year for parts of the Northeast US.
Chilly air for this time of year will settle across much of Canada during the early part of next week and then likely plunge southward into the western US by the end of next week at the same time very warm air surges into the northeastern US. The result of this type of weather pattern at the end of this week could be as follows: 1) snow in places like Denver, Colorado 2) 90 degree readings for the first time this season in places like DC, Philly and New York City and 3) a severe weather outbreak in the central US at the end of next week in the region that will be caught in between these two extreme air masses. So far this season the highest temperatures in the I-95 corridor took place on the 16th of this month with DC peaking at 89 degrees, Philly and Central Park NYC at 87 degrees. This kind of surge of warmth in the Friday/Saturday/Sunday time frame could feature 90 degree readings in much of the Northeast US at the same time the interior western US faces more accumulating snowfall in its higher elevations locations.
One thing that could change this outlook for a surge of warmth into the Northeast US late next week would be if a back door cool front forms in SE Canada and then develops the ability to push southwestward through the region (i.e., gets support from high pressure). At this point in time, odds are against this from happening; however, this is the climatological time of year for back door cool fronts to take place in the Northeast US.
As to whether this expected late April surge of heat into the eastern US foreshadows a hotter-than-normal month of May, the early indications are negative on that notion. In fact, there are signs that the eastern US will cool down early in May relative-to-normal and the cooler weather pattern may last for much of May in much of the nation.
Meteorologist Paul Dorian